Visual indicating device for bad breath

ABSTRACT

The invention provides a breath testing device which includes a visual indicating agent which changes color in the presence of an odor associated with bad breath, such as sulfur and ammonia odors. An example of the visual indicating agent is 4,4′-bis(dimethylamino)-benzhydrol (Michler&#39;s hydrol or BDMB) and related dyes having a similar chemical structure. The indicating agent is applied to a substrate which is then inserted into a tube or straw, or which covers one end of a straw. When a user with bad breath blows into the tube or straw, the indicating agent will change color. The breath testing devices provide a quick and affordable means for a user to test their breath, and they may be packaged in discreet, pocket-sized dispensers which can be carried in a pocket or purse.

RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.10/687,270, filed on Oct. 16, 2003, which is incorporated herein in itsentirety by reference thereto.

BACKGROUND OF THE INVENTION

In the literature, bad breath is usually referred to as halitosis ororal odor. The term halitosis comes from the Latin Halitus, meaningbreath and the Greek -osis, meaning abnormal condition. On one hand mostpeople are not aware of their own breath (whether sweet or bad), whileon the other hand most people usually feel too uncomfortable to inform aperson that they have bad breath.

The breath freshening and oral hygiene areas are large markets which arecontinuing to grow. For example, market research has shown thatconsumers in the USA spent US$1.8 billion on toothpaste in 2000, aroundUS$715 million on oral care gums, almost US$740 million on mouthwash andother dental rinses, and almost US$950 million on toothbrushes anddental floss. Although many of those products are primarily for themaintenance of oral health, consumers also buy them to ensure that theirbreath is pleasant. The US$625 million spent on breath fresheners otherthan gums and mouthwash, for example breath mints, is directly for thispurpose.

The mouth and nasal passages are home to hundreds of bacterial specieswith various nutritional preferences. In otherwise healthy people, thevery back of the tongue, rather than the teeth and gums, is the mainsource of bad breath. This region is poorly cleansed by saliva andcontains numerous tiny invaginations in which bacteria can hide. Thesebacteria putrefy postnasal drip and other oral debris that can collectthere. These tiny organisms thrive on proteins, and the chemicalcompounds that result from the digestion of these proteins include somefetid compounds. At any given time, oral bacteria may be producinghydrogen sulfide (rotten egg smell), methyl mercaptan and skatole (alsopresent in feces); indole; cadaverine (associated with rotting corpses);putrescine (found in decaying meat); and isovaleric acid (the smell ofsweaty feet).

Additional oral sources of bad breath include poor oral hygiene(especially if proteinaceous particles are left between teeth), guminflammation, faulty dental work, unclean dentures and abscesses.Because a steady flow of saliva washes away bacteria and its resultantodorous chemical products, anything that promotes dryness (for example,breathing through one's mouth, fasting, prolonged talking, stress andmany medications) can exacerbate the situation.

Some bad breath seems to be associated with actual periodontal diseaseand is therefore a useful clue to physicians and dentists. The presenceof several key bacteria such as Treponema Denticola, PorphyromonasGingivalis and Bacterioides Forsythesis can be founding plaque or thetongue.

The chemical composition and concentrations of the odorous compoundsassociated with bad breath have been studied and reported in theliterature (Krotoszynski et al, 1977; Tonzetich, 1971). The most commonodorous compound in levels above the human detection threshold ishydrogen sulfide (>250 ppb), followed by other sulfur containingcompounds such as methyl mercaptan and dimethylsulfide. The human nosecan detect hydrogen sulfide levels as low as 0.02 ppm (v/v), and levelsof 0.025 ppm and greater are deemed to be characteristic of bad breathin a person.

While there are numerous products and technologies that cure or treatbad breath, there are surprisingly few devices available on the marketto help identify and alert a user to bad breath.

One clinical instrument which is currently used to measure ppm levels inpatients' breath is the Halimeter™ breath tester (available fromInterscan Corporation, Chatsworth, Calif.), which costs US$1200 and isnot portable. Another device is the BreathAlert™ breath tester(available from Tanita Corporation, Arlington Heights, Ill.). This is asmall hand-held unit which costs about US$25. It uses a heated wire todetect sulfide compounds in a person's breath and gives a read-out infour levels.

The Halimeter™ breath tester has high sensitivity for hydrogen sulfidebut low sensitivity for methyl mercaptan, which is a significantcontributor to halitosis caused by periodontal disease. The BreathAlert™breath tester unit was sensitive to sulfide concentration, but gavedifferent numbers depending on the position of the meter from the mouthand how the user breathed or blew into the unit's intake area.

There are also other devices which use oral bacteria measurements toindicate bad breath (for example, a device available from Soft LinesInternational), but these are very expensive and take time to provide anindication of bad breath, and are therefore not particularly useful to auser who wants to conduct a “spot check” on their breath.

It would be very useful if users were able to check their breath beforemeetings or dates, while at the office or after a meal.

There is therefore a clear need for an affordable, portable and rapidindicator for testing for bad breath.

SUMMARY OF THE INVENTION

As used herein the terms “odorous compound” and “odor” refer to anymolecule or compound detectable to the olfactory system. The term “badbreath” refers to unpleasant odors which are present in a person'sbreath in levels which are detectable by another person. The term“visual indicating agent” refers to a substance, a composition or amaterial that gives a visual indication when a bad breath odor ispresent in a person's breath in a sufficient concentration.

Visual indicating agents that are sensitive to very low levels (>10parts per billion (ppb)) of sulfur and/or amine containing odors wereidentified. On exposure to low levels of these odors the colorindicating agents change color, thereby indicating the presence of badbreath to the user.

Suitable visual indicating agents are 4,4′-bis(dimethylamino)-benzhydrol(BDMD or Michler's hydrol (MH)) and related dyes having the generalformula (I) or (II):

Michler's hydrol was identified and demonstrated to be sensitive to verylow levels (˜20 ppb) of sulfur and/or amine volatile compounds, themajor odorous components of bad breath. This dye was tested for itssensitivity to the various odors in bad breath (sulfurs and amines inparticular, including bad breath caused by fish, garlic, onions and thelike), and was determined to be a good visual indicating agent for badbreath detection.

Simple breath testing devices which contain at least one of theindicating agents were also developed, wherein the indicating agentchanges color when a user has bad breath. The visual indicating agent iscolor sensitive to at least one odor present in bad breath.

The device includes a simple carrier portion defining a passage, such asa substantially transparent tube or straw, containing the visualindicating agent and which is open on at least one end. While theinvention will be described hereinafter with particular reference tostraws and tubes, it will be understood that the invention is usefulwith various other shapes as well. For example, the shape of thepassageway may be cylindrical, triangular, square, almond-shaped and soforth.

The visual indicating agent may be in the form of a powder, in solution,or may be coated onto a substrate, such as cellulose tissue or paper, anon-woven polypropylene/polyethylene substrate, a woven substrate, glassfibre, cotton, silk, rayon and so forth. The straw may be substantiallyflattened to allow for easier storage, while still permitting a patientto blow through the passage in the tube. The device may include a zonewith at least one reference color to allow the user to compare the colorof the indicating agent after exposure to his or her breath with thereference color, and so easily determine if there has been a colorchange.

In one embodiment, the device includes a conveniently sized and discreetplastic tube, such as a clear drinking straw containing the colorindicating agent. The color indicating agent can be applied to a stripwhich is inserted into the straw or over an end of the straw, can beused in powder form or can be incorporated into a solution inside thestraw.

In order to test his or her breath, the user breathes or blows into oronto the device, and a change in color of the indicating agent (whichmay be the fading of color, the development of color or a change fromone color to another) indicates that the user has bad breath. Thisbreath testing device therefore alerts the user of his or her bad breathand allows them to take appropriate action, such as to brush his or herteeth, use mouthwash or eat a breathmint.

A dispenser for containing and dispensing the breath testing devices wasalso developed, and in one embodiment, the dispenser with the breathtesting devices is designed so that it can be sold together with, orlater attached to a dispenser for at least one breath freshening agent,such as toothpaste, breath mints or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a standard curve for the detection of furfuryl mercaptan byMichler's Hydrol-dye;

FIG. 2 shows a standard curve for the detection of ammonia by MH-dye;

FIG. 3 shows simple breath testing devices according to one embodimentof the invention in an unassembled state, and a color change of theindicating agent in response to bad breath (right);

FIG. 4 shows the simple breath testing devices of Example 8, where thecontrol tubes (a) and (e) have not been exposed to odor and tubes (b) to(d) have been exposed to breath odor (Tube (b): exposed to breath odorat BreathAlert™ detector reading of 2; Tubes (c) and (d): exposed tobreath odor at BreathAlert™ detector reading of 3);

FIG. 5 shows a second embodiment of a breath testing device according tothe invention with a color reference before (right) and after (left)exposure to bad breath odors;

FIG. 6 shows a third embodiment of the breath testing device accordingto the invention;

FIG. 7 shows a fourth embodiment of the breath testing device accordingto the invention;

FIG. 8 shows a dispenser for the breath testing devices (right) which isattachable to a dispenser for breath mints (left); and

FIG. 9 shows the dispensers of FIG. 8 when attached to each other.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides simple visual breath testing devices which areable to detect levels of sulfur and/or ammonia compounds in a user'sbreath which are indicative of bad breath. Thus, the breath testingdevices include a visual indicating agent that changes color in thepresence of bad breath. The breath testing device is portable, discreet,disposable and relatively inexpensive to produce.

In one embodiment, the visual indicating agent is4,4′-bis(dimethylamino)-benzhydrol, also known as “BDMD”, “Michler'shydrol” or “MH”. This indicating agent is sensitive to bothsulfur-containing and ammonia-containing odors, changing from blue tocolorless in the presence of these odors. Michler's Hydrol reacts withamine or sulfur compounds according to the following reaction:

In alternative embodiments, the visual indicating agent may be anindicating agent represented by the following general formula (I) or(II):

where,

Indicating Agent R R′ R″ Indicating Agent for Michler's Hydrol(CH₃)₂NC₆H₄— (CH₃)₂NC₆H₄— H Thiols, Mercaptans, (MH) Ammonia, Amines,Diamines and Polyamines Pararosaniline (NH₂)C₆H₄— (NH₂)C₆H₄— (NH₂)C₆H₄—Ammonia, Amines, (PAB) Diamines and Polyamines Alpha- naphtholbenzein(ANB) C₆H₄—

Ammonia, Amines, Diamines and Polyamines Naphthochrome Green (NCG) C₆H₄—

Ammonia, Amines, Diamines and Polyamines

The dye may change color by fading to a lighter color, by deepening incolor or by actually changing from one color to another.

The degree of the color change will depend on the concentration of theindicating agent or the concentration of sulfur or ammonia compounds inthe patient's breath. Therefore, in order to observe a color change inresponse to sulfur and/or ammonia levels >10 parts per billion (ppb),more preferably >20 ppb, and most preferably >25 ppb, the concentrationof indicating agent which is used is preferably in the range of from0.001 to 15% wt/wt, more preferably from 0.005 to 2% wt/wt, and mostpreferably from 0.1 to 0.5% wt/wt.

The substrate, typically a cellulose tissue, may be coated withnanoparticles to provide a high surface area coating on the substrate,i.e., higher than the cellulose fiber by itself. Thus, the cellulosetissue may be given a boost in surface area by coating it with thenanoparticles. The treated substrate may be then coated with the visualindicating dye. It's believed that this high surface area coatingspreads the dye over the silica surface to provide a thinner coating andthus improving the sensitivity of the device.

The average size of the nanoparticles is generally less than about 100nanometers, in fact it may be from about 1 to about 50 nanometers, andfrom about 4 to about 20 nanometers. As used herein, the average size ofa particle refers to its average length, width, height, and/or diameter.

The nanoparticles may have a surface area of from about 50 square metersper gram (m²/g) to about 1000 m²/g, in some cases from about 100 m²/g toabout 600 m²/g, and in some cases, from about 180 m²/g to about 240m²/g.

In addition, the nanoparticles may also be relatively nonporous orsolid. That is, the nanoparticles may have a pore volume that is lessthan about 0.5 milliliters per gram (ml/g), less than about 0.4milliliters per gram, less than about 0.3 ml/g, and even from about 0.2ml/g to about 0.3 ml/g. It is believed that the solid nature, i.e., lowpore volume, of the nanoparticles may enhance the uniformity andstability of the nanoparticles.

Examples of commercially available alumina nanoparticles include, forinstance, Aluminasol® 100, Aluminasol® 200 and Aluminasol® 520, whichare available from Nissan Chemical America Corporation, Houston, Tex.,USA. Alternatively, silica nanoparticles may be utilized, such asSnowtex-C®, Snowtex-O®, Snowtex-PS® and Snowtex-OXS® nanoparticles,which are also available from Nissan Chemical.

Snowtex-OXS® nanoparticles, for instance, have a particle size of from 4to 6 nanometers, and may be ground into a powder having a surface areaof approximately 509 square meters per gram. Also, alumina-coated silicaparticles may be used, such as Snowtex-AK® nanoparticles available fromNissan Chemical.

The breath testing device includes a simple supporting member, such as asubstantially transparent tube or straw containing the visual indicatingagent. The straw or tube may be substantially flattened to allow foreasier storage, while still permitting a patient to blow through thepassage in the tube.

The visual indicating agent may be in the form of a powder, in solution,or may be applied in solution onto a substrate, such as cellulose tissueor paper, cotton, a non-woven polypropylene/polyethylene substrate, awoven substrate, glass fiber, silk, rayon, fabric, fiber, spunbond,synthetic polymer and so forth, and dried, leaving a dried residue. Theindicating agent may also be printed in solution onto the substrate, forexample by using an inkjet printer. The term “in solution” as usedherein refers to a liquid solution of the indication agent in water, anaqueous solution or solvent such as alcohol or toluene.

The breath testing device may include a zone with at least one referencecolor or shade of color to allow the user to compare the color of theindicating agent after exposure to his or her breath with the referencecolor, and so easily determine if there has been a color change.

In one embodiment, the visual indicating agent is coated onto acellulose substrate which is then inserted into a straw. In anotherembodiment, the visual indicating agent is again coated onto a cellulosesubstrate, but is placed over one end of a straw.

In both embodiments, when a user blows into the tube, their breath willpass through the tube and over or through the substrate, thus causingthe indicating agent to change color if levels of sulfur and/or ammoniacompounds which are indicative of bad breath (generally >=25 ppb) arepresent in the user's breath.

According to another embodiment, the breath testing devices describedabove were made smaller in size so that several of the breath testingdevices could be easily packaged together in a pocket-sized container. Astraw was cut to about 4 cm in length, and a dye-treated substrate waseither inserted into the straw or was placed over one end of the straw.The straw was then substantially flattened by laminating it in astandard business card heated laminator so that air was still able topass through the tube of the straw.

A dispenser for containing and dispensing the breath testing devices wasalso developed, and in one embodiment, a pocket-sized dispenser forcontaining and dispensing several breath testing devices was designed sothat it can be sold together with, or later attached to, a dispenser fora breath freshening agent, such as toothpaste, breath mints or the like.

Unless otherwise specified, chemicals and biochemicals were obtainedfrom Sigma-Aldrich of Milwaukee, Wis. Absorbance readings were measuredusing a microplate reader from Dynex Technologies of Chantilly, Va.(Model # MRX).

The most widely used color test is called CIELAB and is discussed inPocket Guide to Digital Printing by F. Cost, Delmar Publishers, Albany,N.Y. ISBN 0-8273-7592-1 at pages 144 and 145. This method defines threevariables, L*, a*, and b*, that correspond to three characteristics ofperceived color based on the opponent theory of color perception. Thethree variables have the following meaning:

L*=Lightness, ranging from 0 to 100. Where 0=dark and 100=light,

a*=Red/green axis, ranging approximately from −100 to 100. Positivevalues are reddish and negative values are greenish.

b*=Yellow/blue axis, Ranging approximately from −100 to 100. Positivevalues are yellowish and negative values are blueish.

Because CIELAB color space is somewhat uniform, a single number can becalculated that represents the difference between two colors asperceived by a human being. This difference is termed ΔE and iscalculated by taking the square root of the sum of the squares of thethree differences (ΔL*, ΔL*, and Δb*) between the two colors. In CIELABcolor space, each ΔE unit is roughly a just-noticeable differencebetween two colors. So that the two colors have a difference of, forexample, 4.4, the human eye can perceive the difference in color betweenthe two colors. CIELAB is therefore a good measure for an objectivedevice-independent color specification system that can be used as areference color space for the purpose of color management and expressionof changes in color.

Color intensities (L*a*b* values) herein were measured using a handheldspectrophotometer from Minolta Co. Ltd. of Osaka, Japan (Model #CM2600d). This instrument utilizes the D/8 geometry conforming to CIENo. 15, ISO 7724/1, ASTM E1164 and JIS Z8722-1982 (diffusedillumination/8 degree viewing system. The D65 light reflected by thespecimen surface at an angle of 8 degrees to the normal of the surfaceis received by the specimen-measuring optical system.

An acetate buffer containing 40 mM sodium acetate and 4 M guanidine HCl,pH 5.1, was used for preparations of the indicating agents.

Paper towels or KIMWIPES® tissues from Kimberly-Clark Corporation ofDallas, Tex., USA were coated with Snowtex-O®) nanoparticles (pH 4.1),available from Nissan Chemical, and were used in the examples describedherein with Michler's hydrol dye (MH or BDMB) where dye was addedwithout acetate buffer, unless otherwise indicated.

The invention will now be described in more detail by way of thefollowing non-limiting examples.

Example 1

1 ml of a reaction mixture was placed into each of 6 vials containing 10μl of furfuryl mercaptan (0, 0.228, 0.456, 0.912, 1.824 and 3.648 ppm,respectively), 980 μl of buffer containing 40 mM sodium acetate and 4 Mguanidine chloride, pH 5.1 and 10 μl of 0.65 mg/ml MH dye (BDMB). Afterincubation of all the vials at room temperature for less than 5 minutes,a 200 μl portion from each vial was transferred to a microtiter platewell, and the absorbances at 590 nm were measured using a microtiterplate reader. The absorbances can also be measured in the range of580-615 nm.

As shown in FIG. 1, a standard curve was derived using furfurylmercaptan as a model thiol odorous compound detectable by MH dye. InFIG. 1 the x-axis is the concentration of furfuryl mercaptan in ppm from0 to 4 and the y-axis is the inverse of the absorbance at 590 nm. Thesensitivity of thiol detection was found to be very high in this method.

Example 2

As garlic is a common cause of bad breath, Michler's Hydrol (MH) wastested to see if it is a sensitive indicating agent for garlic odors.Garlic vapor has a sulfur compound (diallyl thiosulfinate (allicin)) asits major odorous component. Fresh-cut garlic was placed in a jar with aMH-dyed Scott® paper towel, and the jar was sealed. The paper towel inthe garlic containing jar was observed to change color (from blue tocolorless) within 3-5 minutes, whereas no color change was observed in acontrol jar.

Example 3

The experiment was repeated, but instead of using MH dye only, the MHdye was mixed with dyes which are not color sensitive to the odorspresent in bad breath, such as food dyes, in order to create alternativeindicating colors. Exposure of the mixed dye to bad breath odors causedthe MH-dye to become colorless, thus resulting in the area coated withthe mixed dye to change from the mixed color to the food dye color(Table 1).

TABLE 1 Combinations of MH-dye and non-odor sensitive dyes Color AfterDye Color Before Odor Odor Exposure Food Red No. 40 Red Red Food Red40/Michler's Hydrol Purple Red Food Yellow No. 5 Yellow Yellow FoodYellow No. 5/Michler's Green Yellow Hydrol

Example 4

As an alternative to coating a solution of the indicating agent onto acellulose substrate as described in examples 1 to 3 above, a solution ofthe indicating agent was formulated into an inkjet printable ink. Inkjetprinting deposits a thin coating of dye on top of the substrate,potentially allowing a more sensitive color coating on the substrate.The Michler's Hydrol dye solution was formulated with inkjet additivesshown in Table 2 below.

TABLE 2 InkJet formulation INK COMPONENT VOLUME (ml) Water (deionized)0.85 Ethylene Glycol 3.0 Glycerol 1.5 Polyethylene Glycol (200 MW) 3.01,3-Propanediol 1.5 Michler's Hydrol (1.5 mg/ml) in 40 mM sodium acetate40.1 and 4 M guanidine HCl, pH 5.1 TOTAL 50

The ink solution was loaded into empty Margarita™ cartridges (part no.0900400-300) obtained from McDermid-Colorspan of Eden Prairie, Minn. andprinted using a wide format McDermid-Colorspan printer (Model XII). Goodinkjet printing on Scott® paper towel substrate was demonstrated. Astrip of the printed Scott® paper towel was then exposed to garlic odorand the blue color was observed to decolorize in 10 seconds (compared to3-5 minutes taken to observe the color change of a Scott® paper towelsaturated with MH according to one of the previous examples). Highersensitivity to the odor was thus observed by inkjet printing theindicating agent onto the substrate.

Example 5

As shown in FIG. 2, a standard curve was derived using ammoniumhydroxide solution as an ammonia odor source in order to determinewhether MH is a suitable indicating agent for ammonia.

Into each of 8 vials, 50 μl of a specific concentration of ammoniasolution (0, 0.01, 0.02, 0.04, 0.08, 0.16, 0.32, and 0.64%,respectively) was mixed with 150 μl of MH solution (20 μl of 10.0 mg/mlMH in CH₃CN with 5.0 ml of 40 mM sodium acetate and 4 M guanidine HCl,pH 5.1) and the vials were sealed and incubated for less than 4 min.

The solutions were then transferred to microtiter plate wells and theabsorbances were measured at 590 nm. The absorbance readings wereplotted against the concentrations of ammonia solutions, with theconcentrations being represented as parts per billion (ppb). In FIG. 2,the x-axis is the concentration of ammonia in parts per billion (ppb)from 0 to 400 and the y-axis is the absorbance at 590 nm from 1 to 0.7.The sensitivity of MH to ammonia was very high, and it was shown thatthe sensitivity could be altered by varying the MH-dye concentration.

Example 6

As shown in FIG. 3, breath testing devices 10 were made using a simpledrinking straw into which a rolled dye-coated paper towel was inserted.The dye content on the paper towel varied depending on the sensitivityrequired for bad breath testing. Accordingly, 1 mg/ml stock solution ofMH-dye 16 was applied on a Snowtex™-O nanoparticle-coated Scott® papertowel and allowed to air dry. The dye-coated paper towel was then cutinto 2 cm×4 cm strips 12 which were rolled up and each strip 12 wasinserted into a clear plastic drinking straw 14 from Glad ProductsCompany of Oakland, Calif.

The breath testing devices 10 were tested by injecting knownconcentrations of ethyl mercaptan into the straws 14 to determine theirsensitivity to sulphur odors. A color change 18 was noticed and wasclearly visible in the presence of sulphur odors.

Several volunteers were also given a number of these straws and wereasked to blow into them with one lung-full of breath. The tubesdemonstrated bad breath sensitivity, typically with morning breath orafter a spicy meal. Color change of the indicator articles was easilyobservable with an unaided eye, and the color intensities (La*b*) weremeasured using a handheld Minolta spectrophotometer from Minolta Co.Ltd, Osaka, Japan, Model # CM-2600d. An example of the data obtainedfrom one sample is shown in Table 3 below.

TABLE 3 Color intensities of indicating article into which a person withbad breath has blown (expt.) compared with a control article which hasnot been exposed to bad breath SAMPLE L a* b* ΔE Control 66.32 7.27−38.98 — Expt. 74.42 −9.51 −26.69 22.7

Example 7

The simple breath testing devices were tested in a laboratory by havingvolunteers test their breath using the breath testing devices describedin Example 6, a clinical Halimeter™ breath tester and a BreathAlert™breath tester.

Each volunteer first blew into the Halimeter™ and BreathAlert™ breathtesters, and then blew through the visual breath indicating devicestwice, each time with a full lung-full of breath.

The visual indicator devices containing the Michler's hydrol showeddifferent degrees of decolorization of the blue dye. This could be readby the spectrophotometer and the color change measured by comparison ofthe before- and after-exposure samples was expressed as ΔE (the humaneye can only distinguish between samples having differences in ΔE of 3or greater).

The analytical readings taken from the Halimeter™ and BreathAlert™breath testers were then compared to the color change of the straw. Theresults are shown in Table 4 below.

TABLE 4 Comparison of Halimeter ™, BreathAlert ™ and visual indicatordevices of example 6 BreathAlert ™ Halimeter ™ Color Change of HandheldReading For SAMPLE Indicator Tube (ΔE) Meter Reading Sulfur (ppb)Control 0.0 — 10 Volunteer 1 3.0 1 37 Volunteer 2 15.0 2 58

It should be noted that BreathAlert™ breath tester readings of 1 and 2are low bad breath levels, hence the low hydrogen sulfide concentrationreadings from the Halimeter™ breath tester.

Example 8

Following on from the study of Example 7, a larger, more detailed studywas conducted.

As in the previous study described in Example 7, volunteers wererequested to blow into a BreathAlert™ breath tester and then into twobreath testing devices 10 as described in Example 6. This study obtainedhigher levels of bad breath than the previous study, and the results areshown below in Table 5. The breath testing devices used in the study areshown in FIG. 4.

TABLE 5 Correlation of color intensities (La*b*) of the indicator tubeswith bad breath detector (BreathAlert ™) readings Type of Tube indicatorBreathAlert ™ L a* b* ΔE # tube reading value value value value aControl — 60.84 13.04 −46.93 32.1 63.01 9.83 −44.91 27.8 e Control —63.51 8.57 −42.80 25.4 62.95 10.48 −45.54 28.6 — Control — 62.15 9.87−43.75 27.5 62.09 9.99 −43.84 27.6 b Sample 2 71.34 −0.17 −32.33 10.370.13 1.66 −34.44 13.2 c Sample 3 71.92 −2.49 −30.81 7.5 72.72 −2.69−28.65 6.54 d Sample 3 71.06 −4.44 −30.71 6.18 70.51 −2.36 −33.58 9.53

The above color change readings, expressed as ΔE, show the sensitivityof the dye to the bad breath odor. The readings were calculated bycomparing the sample to the white standard. Thus the larger the ΔEvalue, the more colored the sample. As the sample decolorizes onexposure to bad breath, the blue becomes paler in color and this isreflected in the smaller ΔE value, i.e. the color is moving closer towhite. The human eye can distinguish between samples having differencesin ΔE of 3 or greater. Thus, the eye can easily tell the differencebetween samples which had bad breath levels of 2 and 3 (as measuredusing the BreathAlert™ device), as well as the difference between thecontrol and a sample having a bad breath of level 2.

As a result of this sensitivity, it is possible to produce a color scalewhich can inform the user of the intensity of his or her bad breath. Forexample, a panel on the side of a container containing the breathtesting devices could include a color graduation scale, similar to theuniversal pH indicator. This scale would inform the user as to mild,moderate or intense bad breath readings.

The color-based technology was not found to give false negatives, unlikethe electronic devices.

Example 9

KIMWIPES® tissues were coated with a 5% Snowtex-O® nanoparticle solutionfrom Nissan Chemical and then air-dried. 5.0 mg/ml stock solution ofMH-dye in acetonitrile was applied to the Snowtex-O® nanoparticle-coatedKIMWIPES® tissues and a blue color was observed to develop as theapplied dye solution dried.

As illustrated in FIG. 5, a drinking straw 20 from Glad Products Companyof Oakland, Calif., was placed on a cardboard strip 22, and a piece ofthe dye-nanoparticle coated tissue 24 was placed over a first end 25 ofthe straw 20. Thus, when a person breathes into the second end 26 of thestraw, their breath would pass through the tissue 24 at the first end ofthe straw. The straw was placed between two sheets of polyethylene 28which were then heat-sealed so that only the second end 26 of the strawwas exposed. A reference (or control) color strip 30 was also placedbetween the polyethylene sheets near, but separate from, the first end24 of the straw and sealed when the polyethylene sheats were heatsealed. This reference strip was a piece of the dye-coated tissue andallows the user to compare the color of the strip over the first end ofthe straw with the reference strip to see if there has been a colorchange, and hence to determine whether he or she has bad breath (right).The reference strip could also include a scale of two or more shades ofblue so that the user could compare the change of color of the tissueover the straw with the scale, and so determine the degree of his or herbad breath. For example, a slight change in the color could representmild bad breath, a more pronounced fade to a lighter blue couldrepresent medium bad breath, and a complete change from blue tocolorless could represent very bad breath.

A simple study was carried out with 15 volunteers to test whether thebad breath testing device was suitable for indicating whether or notthey had bad breath. The test was a simple “Yes” or “No”, where a colorchange would indicate that the volunteer had bad breath (“Yes”) and nocolor change would indicate that they did not have bad breath (“No”).

Each volunteer was given 3 breath testing devices and was asked tobreathe two full lung volumes into the second end of the straw firstthing in the morning when getting out of bed (the most common time forbad breath). The volunteers were then asked to mark on the tube whetherthey thought they had bad breath.

Of the 45 devices which were handed out, 32 were returned and theresults of this first test are shown in Table 6 below.

TABLE 6 Results from a test to determine the existence of bad breathusing the breath testing article described above Results FalseAssumption^(c)) Volunteer # Tested True True False False Code SamplesPositive^(a)) Negative^(b)) Positive^(d)) Negative^(e)) A 3 2 — 1 — B 33 — — — C 3 2 1 — — D 2 1 — 1 — E 3 1 — 2 — F 2 2 — — — G 3 2 — 1 — H 22 — — — I 3 1 1 1 — J 3 2 — 1 — K 2 1 — — 1 L 3 3 — — — Total 32 23 2 71 KEY: ^(a))True Positive = Color change occurred when the user had badbreath. ^(b))True Negative = No color change occurred when the user didnot have bad breath. ^(c))False Assumption = False assumption of theuser. ^(d))False Positive = User did not believe they had bad breathwhen in fact they did. ^(e))False Negative = No color change occurredwhen user believed they had bad breath.

These results indicate that the bad breath visual indicator devices arevery sensitive and accurately inform the user of the presence of badbreath. Of the 32 devices tested, 22 showed a clear visual color changewhen the user thought they had bad breath. Interestingly, 7 colorchanges were recorded when the user did not think they had bad breath,but in fact they had bad breath. This finding matches the literaturepercentage of people who cannot detect their own bad breath: 22% ofpeople in this study were unaware that they had bad breath, and theliterature reports 25%. Only one breath testing device did not show achange in color when the user believed that they had bad breath.

Example 10

While the breath testing devices described in the previous examples wereshown to be suitable for indicating the existence of bad breath, theywere still believed to be slightly too large in size to be easilyportable and to be able to be carried around discreetly. Furthermodifications to the breath testing devices were therefore made tominiaturize them further, in particular so that they were small enoughso that several could fit into thin breath strip containers which couldbe carried in a pocket or handbag.

Two miniaturized breath testing devices were therefore developed:

a) The first breath testing device (FIG. 7) was prepared by taking thearticle of example 8 (i.e. a drinking straw 40 into which a dye-treatedtissue 42 had been inserted) and making the tube of the drinking strawshorter, for example, 4 cm long. The straw was then placed into astandard business card heated laminator (from Kinko's of Dallas, Tex.)so that the tube was flattened but air was still able to pass throughthe tube.

b) The second breath testing device (FIG. 6) was prepared by taking thearticle of example 9 (i.e. a drinking straw 44 having a dye-treatedtissue strip 46 covering one end), and again cutting it to a length ofapproximately 4 cm. The straw was laminated as above.

Example 11

A dye-coated paper towel was attached to a 25 mm×50 mm strip of anadhesive-coated card material. The dye content on the paper towel varieddepending on the sensitivity required for bad breath testing.Accordingly, 1 mg/ml stock solution of MH-dye was applied on aSnowtex®-O nanoparticle-coated Scott® paper towel and allowed to airdry, before being attached to the strip. A small straw was also placedonto the card and the device was packaged in a polyethylene film coverand the edges were heat sealed. A removable, peal-back polyethylene tabwas then used to cover and temporarily seal the dye-coated paper towel.When the tab was pealed back and a user with bad breath exhaled onto thepaper towel, the MH-dye turned colorless.

Example 12

Suitable dispensers for the breath testing devices were designed. Thesedispensers were relatively small, so that they could discreetly fit intoa pocket, purse or handbag. Dispensers should also be inexpensive as thebreath testing devices are intended to be disposable.

A small plastic rectangular dispenser (approximately 35 mm×60 mm×15 mm)which can hold about six breath testing devices of the type described inExample 10 was designed (FIG. 8), and a slightly larger dispenser forholding 12 breath testing articles is also envisaged. However, it shouldbe clear that a dispenser could be sized to store any number of breathtesting articles.

The dispenser 50 of this example was designed to be attachable toanother dispenser 52 for breath mints, chewing gum, cigarettes or thelike (FIG. 9). The dispensers are permanently attached to each other bymeans of a glue or double-sided tape in one embodiment. In analternative embodiment, the dispenser 52 for the breath testing articlesmay have temporary attachment means, such as a magnet 54, or hook andloop fasteners (not shown) and can be attached to the second dispenser52 as shown in FIG. 9, by means of an oppositely polarized magnet 56attached to the other dispenser 52. Thus, the dispensers can be soldindividually so that only one may be replaced at a time.

While the invention has been described in detail with respect tospecific embodiments thereof, it will be apparent to those skilled inthe art that various alterations, modifications and other changes may bemade to the invention without departing from the spirit and scope of thepresent invention. It is therefore intended that the claims cover orencompass all such modifications, alterations and/or changes.

1. A method of testing for bad breath in a user comprising the steps of:causing the user to blow or breathe onto or into a carrier portion of abreath testing device containing a visual indicating agent that issensitive to bad breath odors, wherein the visual indicating agent isMichler's hydrol; and observing if the visual indicating agent changescolor to indicate that the user has bad breath.
 2. The method of claim1, the device further comprising nanoparticles.
 3. The method of claim1, the device comprising a dried residue of an applied solution of thevisual indicating agent contained on a substrate.
 4. The method of claim3, wherein the substrate is located in a passage of the carrier portionof the device.
 5. The method of claim 3, wherein the substrate coversone end of the carrier portion of the device.
 6. The method of claim 1,wherein the visual indicating agent is dissolved in a solvent andremains in solution within the device.
 7. The method of claim 1, whereinthe visual indicating agent is in powder form.